[PATCH net v3 1/2] net: ethernet: mtk_wed: skip ring reset in wdma_tx_ring_setup for WED v3

[PATCH net v3 1/2] net: ethernet: mtk_wed: skip ring reset in wdma_tx_ring_setup for WED v3

[Zhi-Jun You]

Currently WED v3 tx wdma ring, ring reset happens in a separate code
block unconditionally.

Moreover, v3 has double the size of wdma_desc and has different init
values. mtk_wed_ring_reset doens't deal with that and would corrupt the
wdma_desc.

Fix this by skipping mtk_wed_ring_reset in mtk_wdma_tx_ring_setup for
WED v3.

Fixes: e2f64db13aa1 ("net: ethernet: mtk_wed: introduce WED support for MT7988")
Signed-off-by: Zhi-Jun You <hujy652@gmail.com>
---
Changes in v3:
- new patch addressing WED v3 ring reset issue raised by Sashiko
- Link to the review: https://lore.kernel.org/netdev/20260630144831.1109-1-hujy652@gmail.com/
---
 drivers/net/ethernet/mediatek/mtk_wed.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/mediatek/mtk_wed.c b/drivers/net/ethernet/mediatek/mtk_wed.c
index 10d9beaae372..7d2775a97fa0 100644
--- a/drivers/net/ethernet/mediatek/mtk_wed.c
+++ b/drivers/net/ethernet/mediatek/mtk_wed.c
@@ -1938,7 +1938,7 @@ mtk_wed_wdma_tx_ring_setup(struct mtk_wed_device *dev, int idx, int size,
 	wdma_w32(dev, MTK_WDMA_RING_TX(idx) + MTK_WED_RING_OFS_CPU_IDX, 0);
 	wdma_w32(dev, MTK_WDMA_RING_TX(idx) + MTK_WED_RING_OFS_DMA_IDX, 0);
 
-	if (reset)
+	if (!mtk_wed_is_v3_or_greater(dev->hw) && reset)
 		mtk_wed_ring_reset(wdma, MTK_WED_WDMA_RING_SIZE, true);
 
 	if (!idx)  {
-- 
2.47.3

[PATCH net v3 2/2] net:ethernet: mtk_wed: setup WDMA_RING_TX(0) for non-DBDC MT7986

[Zhi-Jun You]

WDMA_RING_TX(0) is required to set MTK_WED_WDMA_RING_TX for WED RX
but on a non-DBDC MT7986 it is never setup because idx is 1.

Setting MTK_WED_WDMA_RING_TX with WDMA_RING_TX(1) is not feasible because
WED still tries to send through WDMA_RING_TX(0). This is verified with
register dump.

Fix this by calling mtk_wed_wdma_tx_ring_setup if wed is v2 and
rx_ring[0] is not allocated and reset tx_wdma[0] if it's already
allocated.

Fixes: 4c5de09eb0d0 ("net: ethernet: mtk_wed: add configure wed wo support")
Signed-off-by: Zhi-Jun You <hujy652@gmail.com>
---
Changes in v3:
- no change
- Link to v2: https://lore.kernel.org/r/20260711112128.971-1-hujy652@gmail.com
Changes in v2:
- Address warm reset concern raised by AI review.
- Return value concern is skipped until further comment from reviewers.
- Added a comment to explain this special case.
- Link to v1: https://lore.kernel.org/r/20260630144831.1109-1-hujy652@gmail.com
---
 drivers/net/ethernet/mediatek/mtk_wed.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/net/ethernet/mediatek/mtk_wed.c b/drivers/net/ethernet/mediatek/mtk_wed.c
index 7d2775a97fa0..b48abad995d7 100644
--- a/drivers/net/ethernet/mediatek/mtk_wed.c
+++ b/drivers/net/ethernet/mediatek/mtk_wed.c
@@ -2334,6 +2334,13 @@ mtk_wed_start(struct mtk_wed_device *dev, u32 irq_mask)
 		if (!dev->rx_wdma[i].desc)
 			mtk_wed_wdma_rx_ring_setup(dev, i, 16, false);
 
+	/*
+	 * non-DBDC MT7986 allocates only rx_ring[1] and tx_wdma[1] during setup
+	 * but tx_wdma[0] is also needed for WED to function.
+	 */
+	if (mtk_wed_is_v2(dev->hw) && !dev->rx_ring[0].desc)
+		mtk_wed_wdma_tx_ring_setup(dev, 0, MTK_WED_WDMA_RING_SIZE, !!dev->tx_wdma[0].desc);
+
 	if (dev->wlan.hw_rro) {
 		for (i = 0; i < MTK_WED_RX_PAGE_QUEUES; i++) {
 			u32 addr = MTK_WED_RRO_MSDU_PG_CTRL0(i) +
-- 
2.47.3